An electrophoretic display (EPD) forms visible images by rearranging charged pigment particles using an applied electric field. The EPD is formed by combining a large number of “micro-cup” or “micro-capsule” EPD cell structures into a flat panel. Each of “micro-cup” or “micro-capsule” EPD cell structures contains charged particles dispersed in hydrocarbon oil. The charged particles can be titanium dioxide (TiOx) particle approximately one micrometer in diameter. A dark-colored dye is also added to the oil, along with surfactants and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates. When a voltage is applied across the two plates, the particles will migrate electrophoretically to the plate bearing the opposite charge from that on the particles. When the particles are located at the top side of the display, it appears white, because light is scattered back to the viewer by the high-index titanium dioxide particles. When the particles are located at the bottom side of the display, it appears dark, because the incident light is absorbed by the colored dye. If the rear electrode is divided into a number of small picture elements (pixels), then an image can be formed by applying the appropriate voltage to each region of the display to create a pattern of reflecting and absorbing regions.
The EPD device is widely used as electronic paper, for example, for electronic book or electronic newspaper publication. The EPD device has the advantages of very low power consumption. Generally, when the displayed image is not changed it consumes no electricity, while when the displayed image changes it only consumes very limited amount of electricity. An EPD can be self-sufficient if combined with a solar cell component to supply electricity.
Refer to FIG. 9 of a related art, when an EPD and a solar cell are combined, the display area and solar cell are usually in separate areas, which takes additional space from the display area. Thus the solar cell area can not be made very large. If the solar cell is embedded within the display area, the charged particles may block the passage of light to the solar cell due to the nature of the EPD, thereby limiting the efficiency of the solar cell.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.